Apparatus and Method for Constructing Building Boards Using Low Friction Surfaces

Abstract

Discloses is an apparatus and method for utilizing air along a building board forming line for the purpose of reducing friction between the board and the underlying forming tables. The device employs a series of air nozzles that are formed within the face of the forming tables. An air source delivers pressurized air to the nozzles. As completed or partially completed boards travel along the forming tables, an air cushion is created to reduce the friction between the board and the underlying table. The pressurized air can also be used to transport the boards and promote the even distribution of slurry during formation. The various components of the present invention, and the manner in which they interrelate, are described in greater detail hereinafter.

What is claimed is: 
     
         1 . A board forming device with low friction surfaces comprising:
 a gypsum slurry mixing device including a slurry outlet;   a first forming table having a series of nozzles;   a first plenum chamber associated with the first forming table and in fluid communication with the nozzles;   a first air source supplying pressurized air to the first plenum chamber and the series of nozzles;   a lower supply roll supplying a bottom facing sheet to the first forming table, the slurry outlet supplying slurry over the bottom facing sheet;   a second forming table having a series of nozzles;   a second plenum chamber associated with the second forming table and in fluid communication with the nozzles;   a second air source supplying pressurized air to the second plenum chamber and the series of nozzles;   wherein the pressurized air supplied to the nozzles reduces the friction between the bottom facing sheet and the first and second forming tables.   
     
     
         2 . A board forming device comprising:
 a gypsum slurry mixing device including a slurry outlet;   a forming table having an upper surface, a length and a width, a series of nozzles placed along with length and width of the forming table;   a plenum associated with the forming table and in fluid communication with the nozzles;   an air source supplying pressurized air to the plenum and the series of nozzles;   a supply roll supplying a bottom facing sheet to the forming table, the slurry outlet supplying slurry over the bottom facing sheet;   wherein the pressurized air supplied to the nozzles reduces the friction between the bottom facing sheet and the forming table.   
     
     
         3 . The board forming device as described in  claim 2  wherein the nozzles are evenly distributed across the length and width of the forming table. 
     
     
         4 . The board forming device as described in  claim 2  wherein the air source supplies a continuous source of pressurized air. 
     
     
         5 . The board forming device as described in  claim 2  wherein the air source supplies pressurized air in bursts at a set frequency, whereby the pressurized air bursts vibrate the bottom facing sheet and the deposited slurry. 
     
     
         6 . The board forming device as described in  claim 2  wherein each nozzle includes a longitudinal axis that is perpendicular to the upper surface of the forming table. 
     
     
         7 . The board forming device as described in  claim 2  wherein each nozzle includes a longitudinal axis that is angled relative to the upper surface of the forming table. 
     
     
         8 . The board forming device as described in  claim 5  wherein the forming table includes a longitudinal axis bisecting the forming table into first and second halves and wherein the nozzles within the first and second halves are orientated at opposite angles. 
     
     
         9 . The board forming device as described in  claim 5  wherein the forming table includes a longitudinal axis bisecting the forming table into first and second halves and wherein the nozzles within the first and second halves are orientated at opposite angles. 
     
     
         10 . The board forming device as described in  claim 2  wherein the forming table includes a longitudinal axis and peripheral edges and wherein the air source supplies air at a greater pressure proximate the longitudinal axis and air at a lesser pressure proximate the peripheral edges. 
     
     
         11 . The board forming device as described in  claim 2  wherein the forming table includes transfer arms for flipping the board and exposing the bottom facing sheet and wherein each transfer arm includes a series of nozzles that are connected to the air source. 
     
     
         12 . The board forming device as described in  claim 2  wherein the nozzles are angled so as to impart directional movement to the boards. 
     
     
         13 . A method for producing building boards, the method utilizing a supply roll of a facing sheeting, a slurry mixing device, a fluid source, and a forming table including a series of nozzles, the method comprising the following steps:
 unwinding the facing sheet over top of the forming table;   depositing a volume of cementitious material from the mixing device to the unwound facing sheet;   supplying a pressurized fluid from the fluid source to the series of nozzles, whereby a pressurized fluid cushion is created between the unwound facing sheet and the forming table, the fluid cushion reducing the frictional forces otherwise generated between the facing sheet and the forming table.   
     
     
         14 . The method as described in  claim 13  wherein the fluid source supplies a continuous source of pressurized air. 
     
     
         15 . The method as described in  claim 13  wherein the fluid source supplies pressurized air in bursts at a set frequency. 
     
     
         16 . The method as described in  claim 15  comprising the further step of vibrating the deposited cementitious material via the pressurized air bursts. 
     
     
         17 . The method as described in  claim 13  wherein the nozzles are angled and comprising the further step of moving the unwound facing sheet via the fluid cushion. 
     
     
         18 . The method as described in  claim 13  comprising the further step of supplying the pressurized fluid at greater pressures at selection locations upon the forming table so as to promote the even distribution of the deposited cementitious material.